Clamp adjuster



Aug, 30, 1932. v. JULLIEN CLAMP ADJUSTER Filed Nov.A 12, 195o '2 Sheets-Sheet 1 l H HIH lllll HUI vwamtoz M i @Mime/1f W Aug. 30, 1932. v JULLIEN A 1,875,012

CLAMP ADJUSTER Filed Nov. l2, 1930 2 Sheets-Sheet 2.

Patented Aug. 30, 1932 'usura n? stares PATENT OFFIi-c'n VICTORV JULLIEN; or# cINeINNArI, OHIO, Ass-IGNOR rro THE* CINCINNATI BIcx'ioin'* TOOLIOOMPANY, OI oINOI'NNirII; OHIO',l A' CORPO'RA'IION'OF OHIO I CLAMP ADJUSTER Appliation f mea November 12, 1930. f. serial No. 495,084. y

This invention concerns clamping mechanisms and relates particularly! to Lan i m`` proved means for accuratelyv compensating -for'the wear on the'parts'and for accurately s, determining and maintaining la preselected ymeans for compensating Jfor the'wear on the clamping surfaces or on the threads ofa draw bolt and clamp nut or similarclan'iping devices, without changing "the relative angle of the clampingv lever fwhen'jthe latter fis" in a fully tightened position. Unlessl specialad justing means are provided the ordinary'efect'ot the wearv on the clampmgmechamsm isto increase the angle through which the' clamn'lev'er' moves before the' arts are se- A' curely clamped, and itfthe mechanism be 4apof the'parts, thereby toposition thelever plied. to a machine tool', such asfo'r example, a radial drill, the'position of the clamping" lever,y through wear, will gradually'change until a position is reached -where the operator yhas a poor Vpurchaseftor electing a clamping operation and which may seriously 'interfere with the proper operation and functioning of' the 'machine elements. Y

Thisk invention pro oses to overcomethis` undesirable situation v y providing a' means,

readilyaccessible to the `operaton'tor correctl. ing'. and limiting 'the angular movement of the clamp lever wheneverfthere isa tendency otthe latter to exceed a predetermined positionin' effecting a clampingor unclampmg within 'easy and convenient reach Vofthe operat'or to facilitate the clamping ofA the members and at the same timerto insure th'at'the clamping action is complete before the lever reaches ahazardous position.

:further Objeotof this invention is to pro-V vide a single means for regulating the clear- 11 ance between cooperating clamping elements,

` suchgasor example, threaded members, andk orflimitin'g the,l reverse movement ofa clamp` leverto a predetermined position, thereby, to control the degree` of loosenessb'etween the threads of' the clamp nut yJandf screwh and to prevent the clamp lever from being'un'necesl sarilyl turned or dropping of'itsfown weight to adangerous position when the parts'are free or unclamped.

Still another object of this invention'isto provide a clamping mechanism with means for adjustably controlling the range ofmove ment of the actuating means, whether power or manual, so that clamping of the partsm'ay beV effected within a preselected range of movementthereot.

Infthe attainmentof'these results'lipropose y to provide the clamp stud'or draw holt, as the case may be, with an externally threaded sleeve member splined or keyed thereto and held against relative axial movement byl mea-ns of an adjustablelock nut; Upon the movementof'a clamp nut'mounted Vupon the sleeve and engaging the part to be clamped,y or by axially moving thedraw holt, as by power, the parts are securely clamped orunl clamped 'according to the directionof' move ment of' the actuating-,memben The angle.

of'the clamp nut and degree Ottightness ot'l the clamp per given movement of'thel actua# torf being determined by thelock nut whieh shifts the sleeve andl its coacting' member axially along the bolt'toward or away from the clamping surfaces therebyto vary thegap or clearance therebetween. y

Otherv objects and advantages will L be'in part indicated'in the' following description" and 'in part'rendered apparent therefrom-1in connection with the' annexed drawings'.

`To 'enable Others skilled infthe'art'so vfully to apprehend the underlyingfeaturesjhereof that they mayl embody the sameinthefvari" ous. ways contemplated by this" invention, drawings'depicting a preferred typical 'cone struction have been annexed asiaI part of this disclosure and, in suchdrawin-g's, -like= characters of reference' denote corresponding parts throughout all the views, of which:-

Figure l is a Arepresentation of a machine tool incorporating this invention. Fig.y 2 is an enlargedy horizontal sectional `view of a portion thereofillustrating more clearly` the arrangement of the parts Jfor either power or manual operation. Fig. 3 is aview, partly in section, projected from Fig. 2. Fig. 4 is a front view of the clamping mechanism with the lock nut removed. Fig. 5 is a detail view of the lock nut. Fig. 6 is a detail of one form of power clamping mechanism.

Although the annexed drawings illustrate this invention as associated with a drilling machine, it is to be understood that the clamp .adjusting device may be readily adapted to numerous other applications or machinetools wherein it is desirable to clamp two or more members together and to provide a means` for compensating for the wear on the clamping mechanism. v

Fig. 1 illustrates a conventional drilling ymachine of the radial,` type, having averticallydisposed support or post 1 rising from a basemember 2. yA sleeve member'), upon which is translatably ymounted a Ldrill arm 4, is revolvably mounted upon the column 1 and adapted to beV locked or secured thereto in adjusted positions'in a manner later to be Vex-E plained. The drill arm 4 carries a translatable tool head 5 in which are mounted conventional'feed and speed change gears for-the'.v

tool spindle. The spindle driving power is taken, for example, from the motor 7 carried by the arm and enters the headat the rear y thereof in a well known manner.

Under normal working conditions the drill 'head and sleeve member are each adapted to'` be'locked or rigidly clamped to their supports in order to maintain accuracy in the tooling,

operation, and clamping mechanisms, includ- Y ing levers 8'and 9 for the sleeve and head respectively, arev provided for this purpose. However, the continual clamping and unclamping of the members during usage,` as byl re-adjustingthe head 5 toward or away from the column and/or re-adjusting vthe head,

arm, and sleeveabout the' column, gradually causes the clamping mechanisms to become worn, and inthe heretofore used constructions, to the extent that the levers must be turnedV beyond a predetermined pointk in -orderto effect a clamping of the members,

and in some cases,the members may not be clamped even though the vclamping mecha- 'y Vnism is moved to an extreme position.

In order to compensate for the wear on the parts and to thereby correct the angle of the lever when in a clamped position, I have provided the ldraw bolt or stud 10 with an axiall lyl adjustable threaded sleeve member 11 upon which the clamp lever is mounted, a lock nut l2 holds the sleevey in its axially adjusted position'. yInterposed between the hub portion 13 of the lever and the members to be clamped, a wear plate or bushing 14 maybe provided if desired. j j

In order to securelyl lock'the sleeveto the post 1*, the lowerportion of the sleeve is longitudinally and transversely slotted, as lat 15, andthe two wing portions 16 and 17 when cramped towardeach other as by meansof the draw bolt '10, lock the sleeve rigidlyto the post. f

So that power means may be employed for locking the column an electric moto-r 18 1s mounted on the top thereof, which through Va `worm and worm-gear segmentV 19 Aand 2O oscillates a cam shaft 21.` The lower end of the shaft is provided with an eccentric portionl 22 Cwhich engages an eye-piece 23 ofthe,

draw bolt y10, thus, rotation of the cam shaft 2l moves the draw bolt axially to clamp` or unclamp'the column sleeve. Stop lugs 24 and 25 located inthe worm and worm-gear housing v26`limit theextremes of movement.

of thecam shaft torinsure that a continued or prolonged depressing of the motor conf trol switch does notvmove the cam V22 pastl the high and low spots and thus prematurely'. unclamp or clampk the sleeve. llhe motor 18" being of special construction and winding to permit a stalling thereof for several, minutes without burning out.

i After a period of Vusage it willl be noted that.

the power clamping device does not fully clamp the sleeve and kconsequently there is a loss in rigidity of the arm and in increase in tooling errors.,l Compensation forr theV wear` on the parts thus occasioned is made by removing the teat ofthe setV- screw 27 c f from one of the holes 28 formed in the thread;Y

ed sleevemember 11, and then adjusting the nut( angularly one or more divisions. This movement urges the 'sleeve member vinwardly a given distance to take up the wear and lost` motion between the parts.A The teat'of the screw is again inserted in thegnearest hole 28 which coincides with the position of the screw 27. v y Y 'It will be noted that the pin 27 and holes 28, not only provide a means forl'guarding against the working loose or accidental move-V 12 which effects a change in the angle 'of the clamp lever when in clamped position.

miA

For greater accuracy in clamp adjustment l the splined sleeve 11 may beremoved from the shaftlO, turned oneor more positions and replaced, and in this way the number-of axial positions` of the sleeve per revolutionv of the nut 12 is multiplied bythe number j of possible different angular positions of the j sleeve. e n,

As an additional refinement, and inorder to obtain extreme accuracy'in clamp adjustment, the nut 12 may be bored and tapped 1n a number .of places, preferably o-f unequal spacing, so that thepscrew 27 may be inserted 1n any coinciding holes without further adwith respect to the total number i position of the nut into a number of liner dlvisions, it will be seen that extremely close and accurate adjustments of the clamping mechanism may be obtained. Fine adjustments of this nature are highly desirable in order to maintain preselected positions of the clamp lever or power controlled clamping mechanisms when the members are clamped Without unduly stressing the parts or exceeding the capacity of the materials.

It may be mentioned here that the construction and mode of operation of the head clamping mechanism, of which lever 9 forms a part, is in every way similar to the column clamping mechanism above described and detailed description and illustration thereof has been thought unnecessary. Sufflee it to say, however, that the draw bolt 30 slidably but non-rotatably engages a rear face of one of the arm-Ways and upon the'turning of the lever 9, that corner of the head 5 which has a tendency to pull away from the arm during a tooling operation is drawn tightly and securely against its support.

An additional means for taking up the wear on the threads of the sleeve 1l, illustrated more clearly in Fig. et, consists in slotting the hub portion 13 of the lever 8 as at 30, and pinching the parts together as the threads become worn by means of a screw 3l. In this Way a proper lit between the threaded portions may be maintained at all times as well as providing a means for adjusting the frictional resistance between the threads so that the lever Will remain in any position without danger of dropping and ef'- fecting of its own weight, a partial clamping of the members.

The tension varying screw 3l also provides a stop means for limiting the movement of the lever at one of its extremes of movement so that the operator may obtain a goed purchase thereon at all times and so that the power clamping mechanism will not be rendered inoperative when the parts are unclamped manually and conversely.

Without further analysis, the foregoing will so fully reveal the gist of this invention that others can, by applying current knowledge, readily adapt it for various utilizations by retaining one or more of the features that, from the standpoint of the prior art, fairly constitute essential characteristics of either the generic or speeiiic aspects of this invention and, therefore, such adaptations should be, and are intended to be, comprehended within the meaning and range of equivalency of the following claims Having thus revealed this invention, I claim as new and desire to secure the following combinations lents thereof, by States l. A clamping mechanism for a radial drilling machine combining a support; a member mounted thereon and adapted to be clamped thereto; clamping means therefor including a draw bolt, a cam member operatively engaging said draw bolt, a sleeve member adjustable axially on said bolt, and a clamp nut threaded on said sleeve and cooperatively engaging the member to be clamped; power means for rotating said cam member through a limited are to effect clampand elements,

or equiva- Letters Patent of United ing action; means for shifting the sleeve on said bolt to vary the effectiveness of said power actuating means; and means for adjusting said clamp nut angularly to effect clamping action independently of said power means.

2. The combination set forth in claim l characterized by means for varying the effectiveness of the clamping action for a limited angular movement of said clamp nut.

3. A clamping mechanism for a radial drill combining a support; a member mounted thereon and adapted to be clamped thereto; clamping means therefor including a draw bolt, a cam member operatively engaging said draw bolt, a sleeve member adjustable axially on said bolt, a cla-mp nut threaded on said sleeve and cooperatively engaging the member to be clamped; power means for rotating said cam member through a limited are to effect clamping action; means for shifting the sleeve on said bolt to vary the effectiveness of said power actuating means, including a lock nut having a threaded engagement with said draw bolt and adapted to be positively locked to said sleeve in any one of a plurality of dierent angular positions; and means for adjusting` said clamp nut angularly to effect clamping action independently of said power means.

4. The combination set forth in claim 3 characterized by a single means for limiting the angular movement of said clamp nut and for varying the frictional resistance between the clamp nut and said sleeve.

In witness whereof, I have hereunto subscribed my name.

VICTOR JULLIEN. 

